Portable microfilm viewer

ABSTRACT

A portable microfilm viewer is described, which is of compact structure. The viewer includes a control for advance of the microfilm with a lock-out feature whereby single frame advance is deactivated when continuous rapid film advance is selected. The microfilm viewer is adapted to stand upright on a flat surface, with a fold-out viewing screen supported in reading position by side-located shades. The shades fold protectively over the viewing screen when it is not in use, and provide shading against ambient light interference when the screen is in use.

United States Patent 1191 Kaye et al. Feb. 12, 1974 PORTABLE MICROFILMVIEWER 3,124,039 3/1964 Anderson 353/95 [75] Inventors:- Morton Kaye,Stamford, Conn.; FOREIGN PATENTS OR APPLICATIONS Marvin Radlauer, 2Mistletoe DR, 93,272 l/l969 France 353/78 Matawan, Madison Township,860,016 1/1971 Canada 353/74 Middlesex, NJ.

Marvin l Radlauer, Matawan, NJ.

Nov. 1, 1971 Appl. No.: 1%,724

[52] US. Cl 353/26, 353/75, 353/77 [51] Int. Cl G03b 21/11, G03b 21/30[58] Field of Search 353/74-78, 26,

[56] References Cited UNITED STATES PATENTS 3,319,517 5/1967 Rondas .l353/78 3,479,116 11/1969 Anderson 353/77 2,624,231 l/1953 Kingston353/78 2,198,417 4/1940 Scheibell... 352/169 1,762,932 6/1930 Mihalyi..353/96 Primary Examiner-Louis R. Prince Assistant Examiner-A. J.Mirabito Attorney, Agent, or Firm-Louis Altman 1571 ABSTRACT A portablemicrofilm viewer is described, which is of compact structure. The viewerincludes a control for advance of the microfilm with a lock-out featurewhereby single frame advance is deactivated when a use, and provideshading against ambient light interference when the screen is in use.

1 Claim, 9 Drawing Figures PMENTEUFEBTZQ 3.791.728

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INVENTOR. MORTON WAVE WWRWN RADLAUER PORTABLE MICROFILM VIEWER FIELD OFTHE INVENTION This invention relates to a film viewer and morespecifically to a portable microfilm viewer for use at any desiredlocation.

BACKGROUND AND SUMMARY OF THE INVENTION Portable microfilm viewers havebeen previously described as for example in the patents to Allen U.S.Pat. No. 3,498,707, Stoothoff 3,234,848, and Rondas et al. 3,319,517. Ingeneral, such prior art devices have left much to be desired from thestandpoint of compactness, place or position of utility, and versatilityand ease of selection of such control functions as rapid, continuousfilm advance versus single frame advance, forward versus reverse filmmotion, etc.

In a portable microfilm reading device in accordance with the inventiona compact film viewer for displaying images of a microfilm mounted on acassette may be used at any convenient location. The film cassetteincludes a microfilm which bears a large number of frames spaced atregular intervals along the film. A desired frame may be selected fordisplay by advancing the microfilm past a viewing port at a rapid speedtowards a general film region which is known to include the desiredframe. When this film region appears, a frame by frame film advancingcontrol is provided to enable the operator to select the desired framefor display. The control for advancing the microfilm includes a lock-outfeature whereby the single frame advance is deactivated when themicrofilm is rapidly advanced.

The micro-film viewer in accordance with the invention has a compactstructure adapted to stand upright on a flat surface such as a readingtable, with a foldout viewing screen supported in a reading position byside located shades. The side shades are foldably mounted to wrapprotectively around the viewing screen when it is not in use. The sideshades conveniently retain the screen in a reading position whilereducing interference from ambient light.

These advantages and others may be appreciated from the followingdescription of a preferred embodiment of the microfilm viewer inaccordance with the invention.

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a perspective view of amicrofilm viewing device in accordance with the invention and shown inan operative position.

FIG. 2 is a section view of a support bracket employed to retain theviewing screen.

FIG. 3 is a perspective exploded view of the microfilm viewing devicewith the microfilm cassette shown disposed over its mounting area.

FIG. 4 is a top plan view of the microfilm viewer with its coverremoved.

FIG. 5 is a perspective view of optical elements employed in themicrofilm viewer of FIG. 1.

FIG. 6 is a perspective partially broken away view of the film driveemployed in the microfilm viewer of FIG. 1.

FIG. 7 is a perspective view of a control mechanism used in themicrofilm viewer of FIG. 1.

FIG. 8 is a perspective exploded view of a cam and microfilm viewer ofFIG. 1.

FIG. 9 is an electrical schematic of the circuitry used in the microfilmviewer of FIG. 1.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT With reference to FIG.1 a microfilm viewing device 10 is shown in operative film imagedisplaying position. The microfilm viewer has a housing 12 of agenerally rectangular shape to enable the housing to stand upright on atable. The housing 12 has an upper surface 14 from which controlelements project. The control elements include an on/off power switch16, a reversing lever 18, a continuous film advance lever 20 and asingle frame film advance lever 22. The rear housing 12 supports amicrofilm cassette 24. The housing 12 encloses film image projectingoptics which projects images on a translucent viewing screen 26 locatedat a frontal side of the housing. The translucent screen 26 ishorizontally hinged at 28 to fold out as shown into an operative readingposition where it is held by side located shade plates 30-30 havingsuitable retaining brackets 32-32. The shade plates 30-30 are verticallyhinged at 34-34 respectively and fold over the screen 26 to protect thescreen and made the portable film viewer compact when folded down. Theviewing screen 26 is provided with cut-outs 36-36 which are located toreceive brackets 32-32 respectively when the side shades are folded downover the viewing screen 26. r

A mirror 38 is horizontally hinged at 40 to the housing 12 and whenfolded out rests on tabs 42-42 located on side shades 30-30respectively. The brackets 32 and tabs 42 are carefully located toobtain a desired angular relationship between the screen 26 and mirror38, and achieve an undistorted display of images on the screen 26. Theretaining brackets 32, as shown in FIG. 2, each include a U-shapedmember 44 sized to frictionally receive and retain an outer edge of theviewing screen 26.

As shown in FIG. 2 the rear surface of housing 12 includes a cassettesupport area 46 shaped to receive the microfilm cassette 24. The area 46includes a pair of reel hubs 48-48 which respectively engage reels 50-50on the cassette 24. The reels 50-50 may be designated as wind-up andtake-up reels depending upon the desired direction of movement of themicrofilm. The reel hubs 48-48' are provided with ribs such as 52 forpositive engagement with the cassette mounted reels 50-50 in a mannerwhich is commonly used in cassette drives.

The cassette 24 has a viewing frame 54 with an aperture 56 aligned withthe microfilm 58 to view its frames. The microfilm 58 is wound aroundreels 50-50 and threaded with the viewing frame 54 to fit in a space 60formed between portions of an optical projection system such as a lightsource 62 and a reflector prism 64. When the cassette 24 is mounted inarea 46 of housing 12 the prism 64 protrudes into a recess 66 behind theviewing frame 54. The cassette 24 seats against a wall 68 of housing 12in alignment with the microfilm frames and beneath a spring biasedretainer 70 so that the microfilm 58 and viewing frame 54 are accuratelylocated with reference to the optical projection system. Cassettesupporting tabs 71 maintain the cassette 24 in operative positionrelative to the optical projection system. A film gate 72, formed by apair of upright members 74-74, is located in front of wall 68. The filmgate 72 is mounted for pivoting movement about a pin 73 (see FIG. 7) andwhen actuated pivots away from wall 68 in the direction of the arrow 76to enable a film claw 78 to separate itself from sprocket holes in themicrofilm. The film claw 78 is employed to provide incremental filmadvance during frame by frame display of the microfilm 58.

As shown in FIG. 4 the housing 12 is divided into a battery compartment84 sized to retain batteries 86 which provide electrical power for drivetrain 88 located in a compartment 90, and for a light source 62. Thedrive train 88 includes motor 92 and gears 94, 96, 98, 100 and 102. Thepinion 102 is mounted on a worm shaft 103 which protrudes into a controlcompartment 104 to deliver rotation drive. The control compartment 104includes control elements such as the single frame advance lever 22, thecontinuous frame advance lever 20, the on/off power switch 16, thereversing lever 18 and a reversing switch 106. The reversing switch 106and reversing lever 18 are coupled to one another by a bracket 108 (seeFIG. 6). The light source 62, which is powered by batteries 86 throughthe on/off switch 16, shines a beam of light onto the reflecting prism64 through the space 60 where the microfilm passes by.

The worm shaft 103 has a worm 110 which engages a worm wheel 112 mountedon the reversing lever 18. The latter is pivotally mounted to thehousing by a pivot pin 114 which also serves as an axis of rotation forthe worm wheel 112. The worm wheel 112 in turn drives a first pinion 116coupled to a second pinion 118, both of which are mounted on thereversing lever 18. Pinion 118 may engage either one of drive wheels120-120 depending upon which direction the reversing lever is pivoted.Drive wheels 120120 are respectively and coaxially coupled to the reelhubs 4848 (see FIG. 3) so that the microfilm 58 may be moved in thedesired direction.

The single frame advance control lever 22 engages a first control link124 which is pivotally mounted to the housing 12 at 126. This link 124in turn is coupled to a stop shaft 128 which is normally biased by aspring loaded switch contact 130 of a control switch 131 against a stopwheel 132. The stop wheel 132 is coaxially mounted on gear 98. The stopshaft 128 normally engages a recess or slot 134 (see FIG. 7) in the stopwheel 132 to prevent the latters rotation. Another contact 136 of thecontrol switch 131 is operatively disposed opposite the contact 130 toprovide a normally open control switch in series with the electricalpower line to motor 92.

Thus, when the single frame advancing control lever is actuated in thedirection indicated by arrow 138, the link 124 is pivotedcounter-clockwise and moves the stop shaft 128 away from the stop wheeland against contact 130 of control switch 131 to cause the latter toclose and provide electrical power to motor 92. As soon as the motorreceives electrical power it causes a full rotation of stop wheel 132.After one full rotation the stop shaft 128 re-engages the stop 134 inthe control wheel 132 to prevent further rotation and re-open thecontrol switch 131.

During a single control wheel rotation a cam 140 is engaged by a camfollower 142 to operate film claw 78. The cam is coaxially mounted withthe gear 98 and control wheel 132, and operation of the cam and filmclaw will be explained with reference to FIG. 7.

The continuous film advance control lever 20 as shown in FIG. 4 iscoupled to a control member 150 which in turn engages the film claw 78and the film gate 72. When lever 20 is moved in the direction of arrow152 against the bias from springs 154454, the film claw 78 disengagesfrom the film 58. The continuous film advance control lever 20 is alsoconnected to a second control link 156 which is pivotally mounted to thehousing 12 at 157 and has an end 160 connected to the stop shaft 128.Thus, when the continuous film advance control lever 20 is actuated,link 158 is rotated counter-clockwise to move the stop shaft 128 toclose the control switch 131 and release the stop wheel 132. The motor92 may then be continuously actuated to advance the microfilm 58 forrapid movement to a desired region of the microfilm.

The optical viewing system employed with the microfilm viewer is shownin FIG. 5. The electrical light source 62 must operate at a voltagecompatible with the voltage generated by batteries 86. A suitablefocusing lens is mounted in front of the light source 62 and directs thefocused light onto a prism 172 located to reflect the light through themicrofilm 58, prisms 64, lenses 172 and 174 and prism 176 to reflectingmirror plate 38 and then to translucent screen 26. An optical system asthus generally described is of conventional design and conveniently fitsin the compact housing 12.

With reference to FIGS. 6 and 9 the drive and reversing control of themicrofilm viewer 10 may be explained with greater clarity. As shown inFIG. 9, the electrical power from batteries 96 is coupled through powerswitch 16 to light source 62 and the motor 92. Electrical power to themotor may be reversed in polarity by reversing switch 106. Motor power,however, cannot be provided unless the control switch 131 is closed.Motor rotation reversal is accomplished by the lever 18 which is mountedto pass between a pair of spaced elbows 180-180 of reversing bracket108. The reversing bracket 108 is slidably mounted below a cover plate182 which normally encloses the control compartment 104. The reversingbracket 108 is provided with a pair of downwardly extending switchbutton engaging members 184 which are so spaced to enable them toembrace the actuating button 186 of the reversing switch 106. When thereversing lever 18 is pivoted in the direction of arrow 188 the elbow180 of bracket 108 is engaged and the bracket 108 is moved to force theswitch button 186 to its other position and cause a reversal of voltagepolarity to the drive motor, along with a corresponding change in themotor drive train from the reel pinion 120' to the reel pinion 120.

Either single film frame advance or continuous film motion is obtainedwith the interlocked control illustrated in FIGS. 7 and 8 in greaterdetail. The film claw 78 is used to provide an incremental film advancecorresponding to the spacing between successive microfilm frames. Themicrofilm engaging claw 78 is located on a common bracket 190 with thecam follower 142. Bracket 190 is pivotally mounted to the housing by apin 192 which is oriented parallel to the direction of movement of themicrofilm 58. The bracket 190 further is mounted to slide along the pin192 and is held in a preferred position and orientation on pin 192 by aleaf spring 194.

In the single frame advance mode the film claw 78 executes a generallyrectangular path, a portion of which is obtained with the claw 78pivoted towards the film 58 (for film advance), and the remainderobtained with the claw pivoted away from film 58 (for claw returnwithout retracting the film). This film claw motion is produced by theinteraction between the cam follower 142 and cam 140 as moreparticularly illustrated in FIG. 8.

As shown in FIG. 8 the cam follower 142 is formed of a generallyU-shaped extension 196 with a rounded tip 198. The tip 198 extendstowards an annular cam surface 200 which varies in height to cause apivotal motion of the cam follower 142 and thus also the film claw 78.The cam 140 is provided with an eccentrically located hub 202 protrudinginto the aperture 204 formed by the U-shaped extension 196. Hence,rotation of cam 140 produces sliding movement of bracket 190 along thepivot pin 192 as indicated by arrow 206.

The combined effect of the cam surface 200 and hub 202 is a threedimensional movement of the film claw 78. The first motion providesengagement of the film claw 78 with a microfilm sprocket hole, and thisis followed by a movement along the pivot pin 192 to advance the film.The claw 78 then is separated or pivoted away from the microfilm 58 andreturned to an initial position after a complete revolution of the cam140.

When one desires to advance the film by a single frame, the lever 22, asshown in FIG. 7, is momentarily actuated in the direction of arrow 139.This causes the stop shaft 120 to move out of the stop recess 134against contact 130 and close the control switch 131 to energize themotor 92. The cam 140 is now rotated while the stop shaft 120 rides overthe surface 135 of stop wheel 132. During this cam rotation the filmclaw 78 is actuated through its frame advancing motion. When the stoprecess 134 has again rotated opposite the stop shaft 120, the latter ismoved away from switch 131 (under spring action from contact 130) toopen the control switch 131 and prevent further rotation of the cam 140.The angular position of the stop recess 134 relative to the cam 140 isso selected that the film claw 78 is returned to the beginning of asingle frame advancing position each time the stop shaft 120 engages therecess 134.

When one desires continuous film advance, the lever is moved in thedirection of arrow 152 to effect both a release of stop shaft 120 fromthe stop wheel 132 and a pivoting away of claw 78 and the cam follower142. This pivotal movement is obtained by control member 150 which hasan arm 208 to seat against a lip 210 extending upwardly from bracket190. Since the claw 78 may at times tend to pull the film 58 during abackward pivot motion, the film gate 72 is actuated by arm 212 ofcontrol member 150 and thereby made to pivot in the direction of arrow76 to assure claw separation from the microfilm 58.

It will now be appreciated that the present device folds compactly whennot in use, and has provision for forward or reverse rapid andcontinuous film advance as well as single frame operation, all governedby convenient, interlocked function control levers located atop thehousing for ready access during table-top use.

Since the foregoing description and drawings are merely illustrative,the scope of protection of the invention has been more broadly stated inthe following claims; and these should be liberally interpreted so as toobtain the benefit of all equivalents to which the invention is fairlyentitled.

We claim:

1. A pocketable microfilm viewer adapted to occupy minimal area when setup for use upon a horizontal surface, said viewer comprising:

a portable housing having a generally rectangular configuration defininga longer dimension and a shorter dimension;

one surface of said housing providing a substantially planar base forsetting said viewer upon said horizontal surface;

said housing being arranged so that said longer dimension issubstantially normal to said base surface so that said viewer standsupright upon said horizontal surface whereby to occupy a minimum of areathereon;

a retractable viewing screen formed of a translucent material;

means pivotally securing said viewing screen to a portion of saidhousing which is near the upper margin of a vertical surface of saidviewer when the latter is set upright on said housing base surface,whereby said viewing screen is pivotable about a horizontal axis from aposition of storage against said vertical surface to an operatingposition at an angle to said vertical side; i

a reflecting member; means pivotally securing said reflecting member toa portion of said housing which is near the lower margin of saidvertical surface, whereby said reflecting member is pivotable about ahorizontal axis from a position of storage against said vertical surfaceto an operating position at an angle to said vertical side;

a pair of spaced support shades on opposite sides of said viewing screenand reflecting member;

means pivotally securing said shades to a portion of said housing whichis near the side margins of said vertical surface, whereby said shadesare pivotable about a vertical axis from a stored position in which theyfold over and enclose said viewing screen and reflecting member, to anoperative position projecting outwardly from said vertical surface;

said shades each having an edge substantially coplanar with said housingbase surface whereby to help stabilize said viewer in said uprightposition during operation;

means on another vertical surface of said viewer for operativelymounting a microfilm cassette;

means in said housing and projecting therefrom to engage said cassettefor film transport purposes;

a projection system arranged in operative relation to said film cassetteto project images from said film through the lower portion of saidvertical surface;

means on said shades engaging and thereby maintaining said viewingscreen and reflecting member in their respective operating positionswhereby said images are reflected by said reflecting member to saidviewing screen;

and means for governing the operation of said film transport means, andincluding downwardly actuable manual control means projecting from theportion of said housing which is uppermost when said viewer is in saidupright position.

1. A pocketable microfilm viewer adapted to occupy minimal area when setup for use upon a horizontal surface, said viewer comprising: a portablehousing having a generally rectangular configuration defining a longerdimension and a shorter dimension; one surface of said housing providinga substantially planar base for setting said viewer upon said horizontalsurface; said housing being arranged so that said longer dimension issubstantially normal to said base surface so that said viewer standsupright upon said horizontal surface whereby to occupy a minimum of areathereon; a retractable viewing screen formed of a translucent material;means pivotally securing said viewing screen to a portion of saidhousing which is near the upper margin of a vertical surface of saidviewer when the latter is set upright on said housing base surface,whereby said viewing screen is pivotable about a horizontal axis from aposition of storage against said vertical surface to an operatingposition at an angle to said vertical side; a reflecting member; meanspivotally securing said reflecting member to a portion of said housingwhich is near the lower margin of said vertical surface, whereby saidreflecting member is pivotable about a horizontal axis from a positionof storage against said vertical surface to an operating position at anangle to said vertical side; a pair of spaced support shades on oppositesides of said viewing screen and reflecting member; means pivotallysecuring said shades to a portion of said housing which is near the sidemargins of said vertical surface, whereby said shades are pivotableabout a vertical axis from a stored position in which they fold over andenclose said viewing screen and reflecting member, to an operativeposition projecting outwardly from said vertical surface; said shadeseach having an edge substantially co-planar with said housing basesurface whereby to help stabilize said viewer in said upright positionduring operation; means on another vertical surface of said viewer foroperatively mounting a microfilm cassette; means in said housing andprojecting therefrom to engage said cassette for film transportpurposes; a projection system arranged in operative relation to saidfilm cassette to project images from said film through the lower portionof said vertical surface; means on said shades engaging and therebymaintaining said viewing screen and reflecting member in theirrespective operating positions whereby said images are reflected by saidreflecting member to said viewing screen; and means for governing theoperation of said film transport means, and including downwardlyactuable manual control means projecting from the portion of saidhousing which is uppermost when said viewer is in said upright position.